A fatal case of airway obstruction by an organic one-way valve.

We report a fatal case of airway obstruction. A tracheostomized, spontaneously breathing 39-year-old man developed dyspnea, cardiac, and respiratory arrest after tracheal cannula replacement. Inspection of the cannula showed a blood clot obstructing the tube. Autopsy showed pink foam in the trachea, pulmonary hyperinflation, and congested lung parenchyma. Histological examination showed acute pulmonary emphysema without any sign of blood inhalation. The probable pathophysiological mechanism is a clot creating a one-way valve allowing inspiration but not expiration, resulting in dyspnea and pulmonary hyperinflation.